This report summarizes an investigation of the technical, aesthetic, and economic feasibilities of incorporating special noise barrier applications into a highway noise control program. The intent of the report is to take as a starting point the thin, vertical, reflective barrier now used in most applications. Special barrier applications are those beyond the thin vertical reflective barrier.
The investigation of technical feasibility relates to the mathematical formulation of the effects of absorptive treatments, slanted tops, T-tops, and other special applications. The economic and aesthetic feasibility investigations examine the value of employing these special applications in lieu of thin, vertical, reflective barriers.
The research reported on herein was performed on behalf of the Washington State Department of Transportation. The intent of the research was for background studies of the effects of special barrier treatments, so the department could be in a position to implement pilot projects at a later date.